program ize;
const v:array[0..224] of integer=(223,2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,
                                   67,71,73,79,83,89,97,101,103,107,109,113,127,131,137,139,
                                   149,151,157,163,167,173,179,181,191,193,197,199,211,223,
                                   227,229,233,239,241,251,257,263,269,271,277,281,283,293,
                                   307,311,313,317,331,337,347,349,353,359,367,373,379,383,
                                   389,397,401,409,419,421,431,433,439,443,449,457,461,463,
                                   467,479,487,491,499,503,509,521,523,541,547,557,563,569,
                                   571,577,587,593,599,601,607,613,617,619,631,641,643,647,
                                   653,659,661,673,677,683,691,701,709,719,727,733,739,743,
                                   751,757,761,769,773,787,797,809,811,821,823,827,829,839,
                                   853,857,859,863,877,881,883,887,907,911,919,929,937,941,
                                   947,953,967,971,977,983,991,997,1009,1013,1019,1021,1031,
                                   1033,1039,1049,1051,1061,1063,1069,1087,1091,1093,1097,
                                   1103,1109,1117,1123,1129,1151,1153,1163,1171,1181,1187,
                                   1193,1201,1213,1217,1223,1229,1231,1237,1249,1259,1277,
                                   1279,1283,1289,1291,1297,1301,1303,1307,1319,1321,1327,
                                   1361,1367,1373,1381,1399,1409,1423);

var psz,pi:integer;
    n,c,p,x:longint;
    be,ki:text;

procedure kovprim(var p:longint);inline;
begin
 inc(pi);
 p:=v[pi];
end;

function jo(x:longint):boolean;inline;
var i:integer;
begin
 jo:=true;
 i:=1;
 while (i<=psz)and(v[i]<=x) do
  begin
   if x mod v[i] = 0 then
     begin
      jo:=false;
      exit;
     end;
   inc(i);
  end;
end;

function kilo(p:longint):longint;inline;
var i:longint;
begin
 if p=2 then
   begin
    kilo:=(n div 2)-1;
    exit;
   end;
 if p=3 then
   begin
    kilo:=((n div 3)-1) div 2;
    exit;
   end;
 i:=p;
 kilo:=0;
 while i*p<=n do
  begin
   if jo(i*p) then
    begin
     inc(kilo);
    end;
   i:=i+2;
  end;
end;

begin
 assign(be,'ciur.in');
 assign(ki,'ciur.out');
 reset(be);
 rewrite(ki);
 readln(be,n);
 p:=2;
 pi:=1;
 c:=0;
 psz:=0;
 while p*p<=n do
  begin
   x:=kilo(p);
   c:=c+x;
   inc(psz);
   kovprim(p);
  end;
 //writeln(c);
 writeln(ki,n-c-1);
 close(ki);
end.